Increasingly, mobile devices, such as cellular telephones, can transmit or receive text messages. For example, the short message service (SMS) is available for cellular phones, facsimile machines and Internet protocol (IP) addresses. The SMS protocol allows small text messages, with a size less than 160 alphanumeric characters, to be communicated to or from a mobile device. Similarly, the wireless application protocol (WAP) is a specification allowing mobile devices to communicate multimedia messages with one another.
Messaging capability extends the functionality of mobile devices and allows mobile users to send additional information to each other. Commercial vendors have also begun to discover that sending messages to mobile devices is beneficial. For example, systems exist where a commercial vendor can send a message to mobile devices proximate the vendor. Nonetheless, there are problems with the current schemes for sending proximity-based messages to mobile devices, and improved techniques are needed that allow messages to be sent to proximate mobile devices.